Schematic Drawing of VRV Installation
(9) Outdoor unit installation (10) Air tightness test (11) Vacuum drying (12) Additional refrigerant charge
(1) Sleeve work
(2) Indoor unit installation
(6) Duct work (indoor)
(3) Piping support
(5) Drain piping work
(8) Control wiring work
(7) Insulation work
(4) Refrigerant piping work
・ Flaring ・ Bending ・ Pipe expansion ・ Brazing
1. Work Flow by Process
<Process>
<Key Points>
<Page>
Pre-work Determination of the work classification Preparation of the installation drawing
Work (1)
Sleeve work ............................ Consider the downward gradient of the drain pipes. ························································ 2
(2)
Indoor unit installation ............. Confirm the model names to avoid any installation mistakes.·········································· 3
(3)
Piping support
(4)
Refrigerant piping work
(5)
Drain piping work
.................. Maintain a downward gradient of at least 1/100.······························································ 22
(6)
Duct work (indoor)
................ Ensure that a sufficient airflow is maintained. ································································· 26
(7)
Insulation work
(8)
Control wiring work ............... Use applicable two-core wires. ························································································ 30 (Do not use multi-core.)
(9)
Outdoor unit installation
........................ Use supports within the designated support intervals. ······················································ 5 ......... Pay attention to the principles of dry, clean and tight.························································ 9
...................... Ensure that there are no gaps at the joints between insulation materials.·························· 27
........ Make considerations to prevent short-circuiting and maintain a workspace for servicing. 32
(10) Air tightness test
.................... Make a final confirmation that there is no pressure drop at 4 MPaG for 24 hours.··········· 34
(11) Vacuum drying
...................... Use a vacuum pump that can achieve an ultimate vacuum of –100.7 kPaG or lower. ······ 36
(12) Additional refrigerant charge ... Enter the additional refrigerant charge amount onto the outdoor unit and the log book.··· 39
The above order represents the general procedure. It may differ depending on the local conditions and actual circumstances. *Please note that lengths without any units are all in millimeters (mm) throughout this document.
Legend Caution: Points of caution at the job site
One point lesson: Expertise gained from onsite work
Case example: An actual example of onsite work
–1–
2. Work by Process and Key Points
(1) Sleeve work Meeting with the construction company
Work procedure
Determination of the location and sleeve diameter
Installation
Confirmation
~Working points~ ¡ Determination of the placement of the through-holes x Determine the placement so that the drain piping is at a downward gradient of at least 1/100. x Consider the thickness of the insulation material when determining the sleeve diameters for refrigerant piping and drain piping.
10 φＡ
10
φＢ
Insulation thickness: Liquid piping Gas piping
10 10
5
5
Diameter of liquid piping insulation material
<Legend>
Diameter of gas piping insulation material
Upper cell: Sleeve diameter Lower cell: (Calculated value)
Sleeve inner diameter
10 mm 10 mm
φB (gas piping diameter)
φ9.5
φ12.7
φ15.9
φ80 （φ67）
φ80 （φ70）
φ80 （φ73）
φ80 （φ73）
φ19.1
φ22.2
φ25.4
φ28.6
φ31.8
φ80 （φ76）
φ80 （φ80）
φ100 （φ83）
φ80 （φ79）
φ100 （φ83） φ100 （φ86）
φ34.9
φ38.1
φ100 （φ86）
φ100 （φ89）
φ100 （φ92）
φ100 （φ95）
φ100 （φ89）
φ100 （φ92）
φ100 （φ95）
φ100 （φ98）
φ125 （φ101）
φ125 （φ105）
φ100 （φ93）
φ100 （φ96）
φ100 （φ99）
φ125 （φ102）
φ125 （φ105）
φ125 （φ109）
φA (liquid piping diameter)
φ6.4 φ9.5 φ12.7 φ15.9 φ19.1
At least D/4 and 150 mm
2
1
R
L1
R
D
Ì Note that the beam structure limits the allowable area for the placement of through-holes.
L2 L3 At least 3 x [(R1 + R2)/2]
Location into which the sleeve cannot be inserted through the beam
At least D/2
z Cover both ends of the sleeves with masking tape to prevent any concrete from entering
–2–
2. Work by Process and Key Points
(2) Installation of indoor units 1) Work procedure
2)
3)
Determination of installation location
Transporting
4)
Installation of suspension bolts
Indoor unit installation
~Working points~ Installation procedures differ according to the indoor unit model. Be sure to conduct all work according to the accompanying installation manual.
1) Transporting (1) Determine the transporting route. (2) Transport the indoor units to the installation location in the original packing. Do not remove the packing until it is to be installed. (3) When receiving the products, be sure to check for any blemishes or dents. z How to prevent the installation of the wrong indoor unit model or in the wrong location. Before transporting the indoor unit, attach a sheet of paper to a visible spot on the packing that notes the installation location and the system number.
1F reception room AC1-1
2) Determination of installation location
At least 1,500 mm
The following explains the procedure in the event an insert is not contained within the package.
At least 200 mm At least 1,500 mm At least 1,500 mm
(1) Confirm the space required for servicing and installation. (2) Confirm the piping direction and air discharge direction.
At least 200 mm
At least 1,500 mm
Installation space for FXFQ
Ì The space required for servicing and installation may differ depending on the model. Please confirm the details in the installation manual or the like.
Pip in
(3) Mark the center of the indoor unit with chalk lines, using the base point lines drawn on the floor as a guide.
Upper packing material
Unit suspension location
gs
ide
Dra in
sid
e
Center of the unit
Base point line
(4) Using the upper packing material, mark the suspension locations on the floor based on the center of the unit. (5) Use a laser pointer or the like to transfer the suspension location from the floor to the ceiling slab, and use a drill to open up a pilot hole. Ceiling
Laser pointer
Suspension location
Ì If a pilot hole for the anchors leads to a steel beam, be sure to try another location for the hole.
–3–
(2)Installation of indoor units
3) Installation of suspension bolts (1) Determine the length of the suspension bolts according to the height of the installation. (2) Before installing, place the nuts (2; locally procured parts) and washers (2; accessories) on the suspension bolt (double-nut on the lower side of the bolt). (3) After installing, adjust the nut on the lower side to the installation height. (4) For the upper washer, use the attached washer plate to secure. Washer plate (accessory) Insert
Washer (accessory) Upper nut
Suspension bracket Tighten (double-nut)
[Secure the suspension bracket]
Ì Check the installation manual for the installation height when attaching optional accessories.
Steady brace bolt
z The height of the indoor unit can easily be adjusted by loosening the double nut. Re-tighten the double nut after completing adjustment. z The suspension bolt size (M10 or W3/8) is compatible with all models. z If the suspension bolt length is 1.5 m or longer, attach a steady brace on the longitudinal side of the suspension pitch.
An example of steady brace installation
4) Indoor unit installation
(1) Install the indoor unit level. (2) When installing manually, first hook the main unit's suspention bracket onto the suspension bolts on opposing corners to suspend the indoor unit. And, if suspending the indoor unit with a device such as a lifter, remove the lower nut on the suspension bolt before doing so. (3) After installing the indoor unit, be sure to protect it with a plastic bag or the like. Ì If you assume that the temperature and humidity in the ceiling space exceed 30°C and RH80%, reinforce the insulation (thickness) of the indoor unit. (Use polyethylene foam or glass wool with a thickness of at least 10 mm.)
¡ How to protect the indoor unit <Left unprotected>
At least 1,500
[Secure the washer]
<Protected>
Why protect it? Dust and the like can get on the filter and heat exchanger, adversely affecting capacity. Ì After all work is complete, be sure to remove the protective plastic covering and the like from the indoor unit.
–4–
2. Work by Process and Key Points
(3) Piping support (Refrigerant and drain) 1) Work procedure
2) Installation of suspension bolts and supporting fixtures
Determination of location
~The purpose of piping supports~ <Support of horizontal pipes> 1. Prevention of sagging due to their own weight 2. Prevention of spot overloading due to pipe expansion and contraction as a result of temperature differences <Support of vertical pipes> 1. Prevention of swaying and buckling due to their own weight
1) Determination of location ¡ Interval for refrigerant piping support
Vertical pipe
<Horizontal pipes> ≥12.7 ≤2.0 1500
1500
1500
1500
1500
Indoor unit
<Vertical pipes> Pipe outer diameter (mm) Support interval (m)
Supporting fixture
≤44.45 ≤1.5
300～500 Refrigerant piping Ø19.1/Ø9.5 Horizontal pipe
z Adjust based on the liquid piping size when the liquid and gas piping are suspended together.
Ì Upon start and stop of the air conditioner, refrigerant pipes expand or contract due to temperature differences. While it may depend on the particular operation state, the piping can expand or contract 10 mm for every 10 meters. Therefore, be sure to adhere to the required support interval.
¡ Interval for drain piping support (in the case of polyvinyl-chloride pipes) <Horizontal pipes> Pipe inner diameter (mm) Support interval (m)
≤44 ≤1.2
≥56 ≤1.5
<Vertical pipes> Pipe inner diameter (mm) Support interval (m)
≤44 ≤1.5
≥56 At least one spot per floor
–5–
1500
≤9.5 ≤1.5
300～500
Pipe outer diameter (mm) Support interval (m)
(3) Piping support
2) Installation of suspension bolts and supporting fixtures ~Working points~ x Attach refrigerant piping support on top of the insulation material. x With regard to drain piping support, first secure the pipes directly with the supporting fixtures and then place the insulation materials on top of this. ¡ Horizontal piping support z Minimize the length of the suspension bolts z Consider the downward gradient when determining the length of the drain piping suspension bolts. z When supporting the refrigerant piping, place a hard pad (e.g., polyvinyl-chloride pipe) between the supporting fixture and insulation material as shown in the photo to the right in order to prevent crushing of the insulation material from the weight of the piping.
Suspension band with turnbuckle
Polyvinyl pipe
Ì Never provide additional piping support from the piping.
Suspension band with turnbuckle
Suspension bolt supporting fixture (for shaped steel)
Support of horizontal refrigerant piping
Suspension bolt supporting fixture (for flat decks)
¡ Vertical piping support z Allow sufficient space for maintenance and insulation installation when determining the distance between the unit body surface and piping as well as the piping interval when many pipes are laid in parallel.
Anchor Leg for vertical band Vertical band
Vertical piping support (example) Battledore bolt with washer
T-shape leg
Legs for vertical band
Vertical band
Brazing areas Special supporting fixtures for vertical piping
–6–
(3) Piping support
¡ Spot support (refrigerant piping) ~Purposes~ 1. Prevention of overload on areas due to expansion 2. Prevention of overload on the connecting area to the unit due to expansion 3. Prevention of impact on waterproofing due to expansion Support of refrigerant piping branch and bend
300～500
300～500
≤300
≤300 Support points
Support points
300～500
z As shown in the above illustration, it is easier to support the branch piping branches if a different interval is used for each support. Support around the indoor unit Support point
C
A
B
Ａ＋Ｂ＋Ｃ＝300～500 Through-hole support Support point
300~500
300~500
–7–
(3) Piping support
¡ Spot support (drain piping) Bend support
≤300
≤300 Support points
Support around the indoor unit x The horizontal section of the drain piping after the first upward section x The piping connection with the drain hose accessory
Drain hose accessory
Through-hole support
Support point
300~500 300~500
–8–
2. Work by Process and Key Points
(4) Refrigerant piping work 1) Work procedure
2)
Protection (covering)
3)
Pipe processing
Unit connection
~Working points~ x Adhere to the following three basic principles when conducting refrigerant piping work: [The 3 basic principles of refrigerant piping] Dry
Clean
Tight
No water/moisture inside
No dust/contaminants inside
Do not let water/moisture in
Do not let dust/contaminants in
Dust/ contaminants
Water/ moisture
No leakage of refrigerant
Leak
1) Protection (covering) Protection (covering) during storage and work involving refrigerant piping is the most important type of work in order to prevent water/moisture, contaminants or dust from entering into the piping. Ì If water/moisture, contaminants or dust enter into the refrigerant piping, not only will it prevent the air conditioner from operating normally but it will also cause a malfunction of the machine and significant inconvenience for the customer. Your utmost effort is required in preventing this from occurring.
¡During storage (1) Make sure to protect (cover) both pipe ends. Ì Do not use piping that has not been protected (covered). (2) Do not lay refrigerant pipes directly onto a floor surface, but use a table or the like when placing them. <Unprotected (uncovered) pipe ends>
<Protected (covered) pipe ends>
–9–
(4) Refrigerant piping work –Protection-
¡During work (1) Be sure to protect (cover) the ends even when leaving the pipes for a short period of time. (2) Be sure to protect (cover) the ends when pushing a pipe through a through-hole. <Unprotected (uncovered) pipe ends>
<Protected (covered) pipe ends>
[How to protect (cover)] The most reliable is the 'pinch method,' but taping can also be selected as an easy method depending on the site and time frame. Site Outdoor Indoor
Work period
Protecting (covering) method
1 month or more
Pinching
Less than 1 month
Pinching or taping
Not considered
Pinching or taping
<Pinching> A method by which the ends of the copper tube are closed off and the gaps are brazed.
Copper tube Brazing filler metal Braze
<Taping> A method by which the ends of the copper tube are covered with vinyl tape Cut flat
Pipe end
Fold down
Wrap the copper tube with tape.
– 10 –
Wrap with tape again
(4) Refrigerant piping work –Flaring-
2) Pipe processing ¡Flaring…This is one method of connecting refrigerant piping of a diameter of 15.9 mm or smaller to an air conditioner. <Tools>
Reamer
Pipe cutter
File
Flaring tool
Scraper
<Work procedure> (1) Pipe cutting x Use a pipe cutter with left rotation. x Feed the blade of the pipe cutter bit by bit into the pipe with each rotation. Ì Excessive feeding of the blade can disfigure the pipe so special care is required. (2) Processing of the cut surface x x x x
Remove burrs from the tip of the cut surface with a file. Remove burrs from the inner portion of the pipe, using a reamer or scraper. Use the file again in order to remove burrs from the tip. Use the reamer or scraper again in order to remove burrs from the inner portion of the pipe.
Ì When processing the cut surface, face it down to prevent any swarf from falling into the pipe. Ì Make sure that the burｒs are completely removed, as not removing the burrs sufficiently can result in a refrigerant gas leak at the flare.
Burrs
Facing down
Facing down
(3) Flaring x Insert a flare nut into the pipe before flaring. x Ensure that the size of the flare is within the prescribed range. z Note that an appropriate size for the flare is virtually the same as that of the union.
X
Y
X≅Y
Ì The size of the flare will become larger in proportion to Dimension A to the right. Note that Dimension A differs according to the flaring tool manufacturer.
– 11 –
A
(4) Refrigerant piping work –Bending-
¡Bending…Some of the tools used to bend refrigerant pipes are electric-type, hydraulic-type, lever-type and ratchet-type benders. Following is a description of the work procedure with a lever-type bender:
<Tools>
Lever-type bender
<Work procedure> The bending dimensions depend on whether they are taken from the left or right end. (1) Measure the finished dimensions from the right or left end of the pipe.
X From the right
Y From the left
(2) Insert the pipe into the bender. x Align the end of the handle with the '0' mark on the clamping lever.
End of the handle Handle
0
(3) Align the mark on the pipe with the 'R' or 'L' on the handle by adjusting the pipe.
Ｌ
Ｒ
45
0
Pipe
Mark
90
(4) Move the handle to bend the pipe to the desired angle. Clamping lever
Ｘ
Ì Bend the pipe slowly to prevent pleating or deformation of the inner curve of the pipe. Ì Do not bend beyond 90°.
Deformation due to pleating
Deformation due to damage
If the handle does not have the 'L' mark (1) Mark the finished dimension from the left end.
Appropriate bend
End of the handle Handle Ｒ
(2) Insert the copper tube into the bender x Align the end of the handle with the '0' mark on the clamping lever.
0
0
45
(3) Insert the same size of pipe into the bender slot so that the pipe becomes parallel to the clamping lever. Align the center line (middle) of that pipe with the mark on the pipe. (4) Use the handle to bend the pipe to the desired angle.
90
Clamping lever
Ｙ
– 12 –
Mark
Same size of pipe
(4) Refrigerant piping work –Pipe expansion -
¡Pipe expansion…Two pipes can be connected by expanding the end of the refrigerant pipe, inserting the other pipe in question inside and brazing the connection. <Tools>
Expander
<Work procedure> (1) Remove the burrs on the cut surface with a reamer or scraper.
Ì Note that excessive deburring can thin the walls of the pipe and cause vertical (lengthwise) cracking when expanding.
(2) Slightly expand the tip of the head.
(3) Insert the other pipe fully into the tip portion of the head, close the lever and expand the pipe.
(4) This may leave vertical scratches on the inner surface of the pipe so rotate the pipe to remove them.
– 13 –
(4) Refrigerant piping work – Brazing-
¡Brazing…Brazing refers to the use of a metal with a lower melting temperature than that of the base metal as well as the alloy of these metals as solder in order to joint the two base metals without melting them. To heat the solder, a combustion flame of flammable gas (e.g., acetylene, propane) and oxygen is used. The following is an explanation of the work procedure when using acetylene: Ì If certification is required in your country, be sure to have all work conducted by a certified individual. Ì Be sure to wear all the necessary protective gear (e.g., eye protectors, leather gloves), as fire is being used. Ì Always have handy fire prevention equipment such as a fire extinguisher. Ì For solder, use a phosphor copper metal (silver composition: 0%). Ì Don't use a cutting torch. <Tools> For brazing Welding torch
Oxygen regulator
Acetylene regulator (with flashback arrester)
Welding kit Twin hose
z In order to ensure safety when lighting the flame, be sure to use an acetylene regulator with a flashback arrester. [Standards for selecting the outer diameter of the pipe to be brazed and nozzle diameter (French standards)] Outer diameter
Nozzle diameter (mm)
Nozzle number
1.2
#200
Φ22.2
1.3
#225
Φ25.4
1.4
#250
Φ31.8
1.5
#315
Φ38.1
1.6
#400
Φ44.5
1.7~1.8
#450~500
Φ6.4 Φ9.5 Φ12.7 Φ15.9 Φ19.1
Ì If the nozzle is too large, it makes preheating and heating difficult. If too small, brazing takes too long. Use a nozzle that suits the outer diameter of the pipe to be brazed. For nitrogen replacement Tapered nozzle
Nitrogen cylinder
Nitrogen gas regulator
– 14 –
Pressure hose
Valve
(4) Refrigerant piping work – Brazing-
<Work procedure> Procedure 1. Confirmation of an appropriate gap between the pipe and joint z An appropriate gap is when the pipe can be inserted into the joint and held upside down without falling.
Procedure 2. Nitrogen replacement Purpose A voluminous oxide film develops on the inner surface of the pipe during brazing. The film can clog, among other parts, the solenoid valve, capillary tube and compressor's oil pump inlet, hampering normal operation. In order to prevent this from occurring, it is necessary to replace the air within the pipe with nitrogen. This work is referred to as nitrogen replacement. (1) Set up the required tools as shown below: Taping
N2
Pressure hose
N2
Nitrogen gas regulator Taping
Tapered nozzle Valve
Nitrogen cylinder
z It is even more effective to open up a small hole in the tape to release the nitrogen after covering the end of the pipe with tape or the like. z Use of the tapered nozzle results in efficient replacement. (2) Adjust the nitrogen gas pressure to 0.02 (MPaG) or so. Ì If the nitrogen pressure is too high, it may cause the brazing filler metal (solder) not to reach completely around the pipe or pinholes to develop in it. Make sure that the pressure is not excessively high. Ì Use of nitrogen with a purity of at least 99.99% is recommended. Be sure to note that use of a lesser purity nitrogen may likely result in oxide film formation.
The effects of nitrogen replacement
No nitrogen replacement The inner surface of the pipe has blackened due to the oxide film.
– 15 –
Nitrogen replacement The inner surface of the piping is clean.
(4) Refrigerant piping work – Brazing-
Procedure 3. Preheating <The five key points for preheating> Point 1: Heat both base metals evenly. (The inner and outer pipes and the circumference)
Inner pipe
A
A
B
780°C
780°C
600°C
400°C
780°C
780°C
780°C
600°C
Broad heating range
Appropriate heating range
Inner pipe
B
Outer pipe
Outer pipe
A and B Same temperature
A and B Large temperature difference
Uniform temperature around the circumference
Non-uniform temperature around the circumference
Point 2: Heat until an appropriate temperature for applying the brazing filler metal (solder). 640~780°C (where the base metals change color from reddish black to red)
Too early to apply the brazing filler metal (base metal temperature of 500 to 600°C)
Appropriate timing for application of solder material (base metal temperature of 640 to 780°C)
Point 3: Torch flame adjustment and flame intensity adjustment x Conduct brazing with a reducing flame.
Outer flame
Too late to apply the brazing filler metal (base metal temperature of 800 to 1,000°C)
Carburizing flame
Flame core
(Roughly a 5 cm carburizing flame)
x Change the flame intensity according to the size of the base metal.
Point 4: Flame angle (heat control) x Make the flame angle 80 to 85°.
Roughly 5 cm
80–85°
Roughly 5 cm
– 16 –
(4) Refrigerant piping work – Brazing-
Point 5: Visual confirmation
x Distance from the carburizing flame tip x Flame location x Flame direction Carburizing flame
Carburizing flame
Roughly 5 mm
2~3mm
Distance from the carburizing flame tip
Flame location
Flame loss 2~3 mm
Flame direction
Procedure 4. Brazing filler metal application <Five key points when applying the brazing filler metal> Point 1: Confirm the range of brazing filler metal application (spread range)
Overlap
– 17 –
Not overlapping results in a gas leak
(4) Refrigerant piping work – Brazing-
Point 2: Confirm the volume of the brazing filler metal flow (differs according to the base metal heating range)
Appropriate heating range
Excessively broad heating range
Excessively narrow heating range
Excessive flow of brazing filler metal
Lack of flow of brazing filler metal
Point 3: Melt the brazing filler metal from the rod tip (melt it gradually, gently applying it upon the base metal)
Hanging brazing filler metal
Point 4: The angle of flame and brazing filler metal x Increase the flame angle slightly compared to preheating During brazing
80~85°
During preheating
x Make the angle between the brazing filler metal and flame roughly 90°. Brazing filler metal Brazing filler metal Roughly 90°
– 18 –
(4) Refrigerant piping work – Brazing-
Point 5: Confirm visually. (Final confirmation of the distance from the carburizing flame tip, location of flame on the pipe and flame direction)
2~3 mm
Distance from the carburizing flame tip
1~2 mm
Location of flame on the pipe
Flame direction Final confirmation (Move the flame up/down and left/right at a right angle to the pipe)
Facing sideways
Facing down
Facing up Relatively difficult
Relatively easy
z It is relatively easy to apply the brazing filler metal when the pipe is facing down or sideways. But, if the pipe is facing up, it is relatively difficult to spread it and can result in a refrigerant leak. Therefore, make efforts to enable brazing with the pipe facing down or sideways.
Procedure 5. Cooling x Cool the brazed location with a moist cloth or the like to enable work afterward and prevent burns. z Do not turn off the nitrogen until the pipe is completely cooled down. If the nitrogen gas is stopped before the pipe has sufficiently been cooled down, it will result in the development of an oxide film on the inner surface of the pipe.
– 19 –
(4) Refrigerant piping work – Refrigerant branch pipe (REFNET joint) –
¡ Refrigerant branch pipe (REFNET joint) <Installation standards> 1. Install the REFNET joint horizontally or perpendicularly.
Horizontal Ａ
A. Arrow view Perpendicular <Horizontal pipe>
<Vertical pipe>
2. Install the REFNET header horizontally. Example of liquid-side header installation
Example of gas-side header installation
Ceiling
Ceiling
Supporting fixture (locally procured)
Horizontal
Horizontal Mount (locally procured)
z Create at least 500 mm of a straight pipe section before and after branches when connecting refrigerant branch pipe to the field pipe. <Reason> Bending the pipe too close to the branch can lead to complaints about abnormal noise.
At least 1,000
At least 500
At least 500 <Top view>
¡ Example of refrigerant branch pipe installation <Installed at a 90° angle>
<Installed horizontally>
Installing the REFNET joint while it is leaning at an angle can cause refrigerant drift, resulting in abnormal noise or preventing normal operation. Be sure to install it horizontally.
– 20 –
(4) Refrigerant piping work – Flare connection –
3) Unit connection ¡Flare connection <Tools, etc.> Torque wrench
Refrigerant oil
<Work procedure> (1) Apply refrigerant oil (ethereal oil, ester oil) to the inner surface of the flare. (2) Turn the flare nut 3 or 4 times to the machine union side by hand.
Where the refrigerant oil is applied
Ì Be sure to use the flare nuts that come with the unit. Ì If the flare nut cannot be turned by hand, there may be a shaft misalignment of the flare and union. Please try again. (3) Tighten to the prescribed torque value using the torque wrench Ì Tighten, using a technique that employs both the torque wrench and (spanner) monkey wrench. Ì Be careful, as tightening excessively can cause gas leakage due to flare nut cracking and the like. Tightening torque standards for flare nuts Pipe outer diameter
Tightening torque (N•cm)
Φ 6.4
1420~1720
Φ 9.5
3270~3990
Φ 12.7
4950~6030
Φ 15.9
6180~7540
Φ 19.1
9720~11860
z When tightening with a spanner (monkey wrench) because a torque wrench is unavailable: x When tightening a flare nut with a spanner, there comes a point where the tightening torque increases rapidly. From that point, tighten only with an angle shown in the table below. Ì Note that tightening the flare nut with a spanner longer than the recommended tool length shown in the table below can result in excessive tightening.
Φ 6.4
Tightening angle (rough standard) 60°~90°
Recommended length of tool being used Approx. 150 mm
Φ 9.5 Φ 12.7 Φ 15.9
60°~90° 30°~60° 30°~60°
Approx. 200 mm Approx. 250 mm Approx. 300 mm
Φ 19.1
25°~35°
Approx. 450 mm
Pipe outer diameter
Tool length
z Marking the flare nut with a magic marker or the like after it has been tightened prevents the worker from forgetting to tighten the flare nut. Marking
– 21 –
2. Work by Process and Key Points
(5) Drain piping work 1) Work procedure
Indoor unit installation
2) Indoor unit side drain piping
3)
Collective drain piping
Drain flow test
~Working points~ x Ensure a downward gradient of the drain piping of at least 1/100. x Keep the drain piping as short as possible in order to prevent air pockets.
Indoor unit Downward gradient of at least 1/100 (1 cm/1 m)
Ì Do not connect drain pipes to the building's sanitary sewer pipes or waste pipes as it may cause an odor problem.
¡ Reverse gradient of the drain piping In some cases it is difficult to ensure the required drain piping gradient within the ceiling spaces when other piping and equipment crowd the area. Most of such problems can be averted by prior consultation with the installers handling the other equipment. 1/100 gradient
1) Indoor unit side drain piping Ì The installation procedures for drain piping at the indoor unit side differ by the model, so always check the installation manual before installing. Ì Indoor units in which the drain piping connection becomes a negative pressure require a drain trap (see below) for each unit. In addition, the drain trap requires a cleanout for cleaning. Example of drain trap installation Indoor unit FXMQ
Indoor unit FXMQ
H H: At least 50 mm
H
Cleanout Attach a cleanout to allow for cleaning
Drain trap
– 22 –
(5) Drain piping work
<Work procedure> (1) Connect the attached drain hose (flexible type) to the indoor unit's drain outlet. Ì Be sure to use the drain hose that comes with the unit. The flexible type prevents any undue stress on the drain pan. Ì Do not bend the drain hose in the middle so as to prevent any excessive force on it. Bending can lead to a water leak. (2) Tighten the indoor unit's drain connection and drain hose with the attached hose band. Ì Do not attach the indoor unit's drain connection and drain hose (accessory) with adhesive. It complicates removal of the drain hose from the machine during maintenance and the like. Indoor unit
Hose band Attached drain hose Insulation material (piping section)
Drain pain
Insulation material (band section)
(3) Install the drain branch piping up to the main drain pipe.
z Refer to the illustration below for connection from the indoor unit to the main pipe. Allows for adjustment of the angle Main drain pipe
Example of installation
¡ If the main drain pipe has already been installed and the required gradient for the drain branch piping cannot be achieved, maximize the drain-up height. (Confirm the drain-up height with the installation manual as it differs depending on the model.) Drain branch piping Main drain piping
Drain-up height
– 23 –
(5) Drain piping work
2) Collective drain piping z An example of a connection from the main drain pipe to a vertical pipe It is ideal to use a Y joint. If it is not locally available, a T joint can also be used.
Y joint T joint Connection to vertical pipe with a Y joint
Connection to vertical pipe using a T joint
z Maximize the size of the main drain pipe as much as possible. z Attach a cleanout (cap) at the top of the main drain pipe for water flow tests. z Minimize the number of indoor units per group as few as possible in order to prevent the drain piping from becoming too long.
Cleanout Drain branch piping
Vent piping
Vertical drain piping Main drain piping
Example of drain piping installation
3) Drain flow test (1) Conduct a drain flow test before insulation work. (2) Use the cleanout on the main drain pipe for the water flow test. z In the case of polyvinyl piping, use of colored adhesive prevents workers from forgetting to replace the plug.
â&#x20AC;&#x201C; 24 â&#x20AC;&#x201C;
(5) Drain piping work
(Reference) Inner diameters of the main drain piping and vertical drain piping x Calculate the drainage volume based on the number of indoor units connected to the main drain pipe. The inner diameter of the piping can be determined using the following method: x 6 liters per hour per 1 HP is a rough measure for drainage volume from the indoor units. For example, in the event of 3 units with 2 HP and 2 units with 3 HP: 6 L/hr × 2 HP × 3 units + 6 L/hr × 3 HP × 2 units = 72 L/hr. (1) The relationship between the inner diameter of the main drain pipe and allowable drainage volume when using collective piping (in the case of an air vent) PVC
Inner piping diameter
Allowable flow rate [L/hr]
Comments
(Reference value: mm)
Gradient=1/50
Gradient＝1/100
PVC25
19
39
27
Not suitable for the main drain
PVC32
27
70
50
piping due to the limited allowable flow rate
PVC40
34
125
88
PVC50
44
247
175
PVC63
56
473
334
Suitable for the main drain piping
Note: Calculated assuming that the water ratio within the piping is 10%. Round off the allowable flow rate to the nearest whole number. The pipe after collection should have an inner diameter of at least 34 mm.
(2) The relationship between the inner diameter of the vertical drain pipe and allowable drainage volume when using collective piping (in the case of an air vent) PVC
Inner piping diameter (Reference value: mm)
Allowable flow rate [L/hr]
PVC25
19
220
PVC32
27
410
PVC40
34
730
PVC50
44
1,440
PVC63
56
2,760
PVC75
66
5,710
PVC90
79
8,280
Comments Not suitable for vertical drain piping in the case of collective piping
Can be used for vertical drain piping in the case of collective piping
Note: Round off the allowable flow rate to the nearest 10. Vertical pipes within collective piping should have an inner diameter of at least 34 mm.
– 25 –
2. Work by Process and Key Points
(6) Duct work (indoor)
Work procedure
Indoor unit installation
Air inlet/outlet installation
Duct connection
~Noise and vibration considerations~ x Be sure to use canvas joints between the indoor unit and suction ducts as well as the indoor unit and discharge ducts. This is because they are useful in preventing reverberations when the product's vibrations and operating noise travel through the building and ducts. Suspension bolt Canvas duct
Canvas duct Indoor unit
x Select suction and discharge grilles in consideration of the airflow rate so as to prevent any air distribution noise (wind roar).
Ì Be sure to insulate the discharge duct. Ì Use canvas ducts with a metal framework on the inlet side. Ì Consider the positioning of the suction and discharge grilles so as to prevent short-circuiting. Ì Check the static pressure so the prescribed discharge air flow rate is being produced. Ì Make it so the air filter is easy to remove when necessary.
– 26 –
2. Work by Process and Key Points
(7) Insulation work Refrigerant piping work
Insulation work (other than the connections)
Air tightness test
Insulation work (the connections)
Drain piping work
Insulation work (other than the connections)
Drain flow test
Insulation work (the connections)
Work procedure
~Working points~ Insulation work does not allow for checks/tests, so ensure that any maintenance and repair on the insulation joints and the like is done properly. [Materials] For the insulation, use materials that can sufficiently withstand the temperature of the piping. <Refrigerant piping> x Heat-pump type…Heat resistant polyethylene foam (that can withstand temperatures over 120°C) x Cooling-only type…Polyethylene foam (that can withstand temperatures over 70°C) <Drain piping> x Polyethylene foam (heat resistant temperature: –70 ~ 80°C) Ì If you assume that the temperature and humidity around the refrigerant pipe might exceed 30°C and RH80%, please use insulation with a thickness of 20 mm or more. Ì Polyethylene foam insulation material cannot be used in some areas (Hong Kong) due to the fire codes. Therefore, confirm this in advance. Ì Be sure to insulate connections (brazed, flared, etc.) after they have passed air tightness tests. Ì Be sure to insulate both the gas and liquid piping individually.
Insulate both the gas and liquid piping together Liquid piping
Gas piping
Insulation material
Insulate only the gas piping Liquid piping
Insulation material
Gas piping
Insulate the gas and liquid piping individually Gas piping
Liquid piping
Insulation material
Insulation material
Ì Be careful not to leave any gaps in the insulation joints. Ì Be careful not to use damaged insulation material.
Gap in the insulation joint
Damaged insulation material
– 27 –
(7) Insulation work
¡ Indoor unit flares x Use the following guide to conduct insulation work properly up to the base of the refrigerant piping on the indoor units. Flare insulation work guide
Wind from the base of the machine to the upper portion of the flare nut connection
Piping insulation material Joint insulation material (accessory) (machine side) Face the joint upward
Piping insulation material (locally procured)
Flare nut connection
Attach to the base
Clamp material (accessory) Tighten the section that overlaps with the piping insulation material
Sealer (accessory) (only gas piping side)
Gas piping Liquid piping
(1) Wind the joint insulation material (accessory) around the flares on both the liquid and gas piping. z Always face the joint of the insulation material upward. (2) Securely fasten both ends of the joint insulation material with the clamp material (accessory). (3) Wind sealer over the joint insulation material only for flares on the gas piping side. Ì Be sure to always conduct the above work after the air tightness test.
¡ Supporting fixture insulation z When supporting the horizontal piping, the weight of the piping tends to crush the insulation at the support spots and cause condensation. At support spots, either reinforce the insulation material using tape with insulating properties or provide support with a hard-type wide polyvinyl tube to spread the weight. z Be careful not to wind any adhesive tape used for a temporary hold too tightly. Insulating reinforcement tape (5t × 50w) Insulation material Supporting fixture
Suspension band with turnbuckle
Polyvinyl tube Example of a polyvinyl tube being used
¡ Reinforcement of the insulation material cuts z Insulation material shrinks with time, so it is recommended that the insulation material cuts be reinforced with tape with insulation material after applying a special adhesive.
– 28 –
(7) Insulation work
¡ When inserting the insulation material into a gap z In consideration of possible shrinking of the insulation material in the future, insert insulation material that is 200 mm longer than the gap into the gap. The work that follows is the same as the above-mentioned (3).
Ｌ
Ｌ+200
L + Approx. 200 mm of insulation material
¡ Reinforcement of insulation material at bends z Try to minimize the number of cuts in the insulation material (one cut is ideal). z Consider where to cut the insulation material so that its reinforcement after bending can be conducted at a straight pipe portion.
Special adhesive
Reinforcement tape with insulation material
– 29 –
2. Work by Process and Key Points
(8) Control wiring work ~Working points~ x Prepare a system diagram and check your work to prevent miswiring.
[Compatible wiring types] Use the following 2-wire sheathed vinyl cords or cables: x Vinyl cabtyre cord (round type)
VCTF
JIS C3306
x Vinyl cabtyre cord (flat-round type)
VCTFK
JIS C3306
x 600V vinyl-insulated vinyl cabtyre cable
VCT
JIS C3312
x 600V vinyl-insulated vinyl sheathed cabtyre cable (round type)
VVR
JIS C3342
x Vinyl-insulated vinyl sheathed control cable
CVV
JIS C3401
x Instrumentation cable with braided screen (shielded wire)
MVVS
JIS C3102
Conductor Insulation Sheath <Example> Cross-section of a VCTF
Ì If shielded wires are not properly grounded on one end, it can lead to communication problems. Therefore, when using a shielded wire, be sure to ground one end.
Ì 1. Use wires of a thickness between 0.75 mm2 and 1.25 mm2.
<When using wires of other sizes> ¡ Thin type When wiring over an extended distance, transmission may become unstable due to the drop in voltage. Moreover, it predisposes the wiring to noise effects. ¡ Thick type When using daisy-chain wiring, 2 wires cannot be inserted into the indoor terminal block.
In the case of a thick type 2 wires cannot be inserted into the terminal block
Ì 2. Never use multi-core wiring (more than 2 cores).
<When using multi-core cables (more than 2 cores)> ¡ Signal interference occurs, resulting in transmission errors. [When using multi-core cables: Example of the VRV series] Indoor
RC
Indoor Normal condition (when sending)
4-core cable (stray capacitance between cables)
RC Interference condition (when sending)
¡ The same thing that happens when using multi-core cables will occur when many single-core wires are inserted into the conduit.
– 30 –
(8) Control wiring work
Ì 3. Never bind communication wires over an extended distance.
<If communication wires are bound> ¡ The insulation distance between wires shortens, predisposing the wires to interference. Indoor unit
RC
Indoor unit
RC
Ì 4. Never wire with bound control wiring
<If control wires are bound> ¡ Strong and weak currents may mix together, so it is recommended not to use multi-core wires. (It affects the wire withstanding voltage among other things.) [Good example]
[Poor example] Remote control PCB
Remote control PCB
Start/Stop
(6-core wire)
Start/Stop
Ì 5. Keep the control wiring and power wiring separate
<If the power wire and signal wire are laid parallel> ¡ Due to the influence of the electrostatic and electromagnetic coupling, a disturbing wave that interferes with the signal wiring is induced, leading to malfunctions. ¡ When laying the signal wiring parallel to the power wiring, it is recommended to separate them with a distance shown in the table below: Power supply capacity for power wiring 220V or more
Separation distance between power wiring and control wiring for Daikin air conditioners
Less than 10A 50A
Separation distance between power wiring for other equipment and control wiring for Daikin air conditioners At least 300 mm
At least 50 mm
At least 500 mm
100A
At least 1,000 mm
More than 100A
At least 1,500 mm
Ì 6. Use the same type of wires for power wiring within the same system.
<If different types of wires are used for power wiring within the same system> ¡ Mixing the wire types can lead to communication problems.
– 31 –
2. Work by Process and Key Points
(9) Outdoor unit installation Work procedure
Foundation preparation
Outdoor unit installation
¡ Precautions when preparing foundations for outdoor units
・
・ ・
Support the unit with a foundation that is at least 66 mm wide When attaching the rubber cushion, attach it to the whole bearing face of the foundation The height of the foundation should be at least 150 mm from the floor Secure the unit to the foundation using the foundation bolts, nuts and washers (Use four sets of M12-type foundation bolts, nuts and washers) The optimum length of the foundation bolts from the surface of the foundation is 20 mm
20
・ ・ ・ ・
Make considerations for the drain outlet Pay attention to the floor strength and waterproofing when installing outdoor units on the roof.
A (Foundation bolt hole)
Model RXYQ5P RXYQ8P RXYQ10P RXYQ12P,14P RXYQ16P,18P
At least 765
4-15×22.5
631
722～737
B
A mm 635
B mm 497
930
792
1240
1102
At least 67 Foundation drawing for outdoor unit
For anything 8 HP or above, use of small concrete blocks at the four bottom corners of the outdoor unit as a foundation is not possible. However, this is possible with the 5 HP models.
Required for any machine of at least 8 HP
Required for any machine of at least 8 HP Middle of the machine
Middle of the machine
– 32 –
(9) Outdoor unit installation
¡ Securing space for servicing/maintenance It is important to make considerations for space for servicing/maintenance. Ì Note that replacement of the compressor may become difficult depending on the piping route.
Not enough space for servicing/maintenance! (Impossible to remove the compressor.)
Foundation
¡ Prevention of short-circuiting Short-circuiting can occur if the outdoor unit is not installed in a location with good ventilation. Ì Note that it may be necessary to install discharge ducts in cases as shown in the illustrations below: <When installing under eaves>
<If there are horizontal obstacles above>
x N ≥ M when L ≥ 1 m.
x No special measures are required if L ≥ 3 m.
x K ≥ M when L < 1 m.
x If L < 3 m, a discharge duct with
Note that Dimension K refers to the dimensions
duct resistance of less than 8
necessary when installing a single unit.
mmH2O is necessary.
Refer to 'Standards for installing
Dimension K for single unit
upward-discharging outdoor units' when
installation requires being
installing on each floor.
slightly larger.
Discharge duct For short-circuiting prevention
Measures for obstacles above
Installing under eaves
¡ Considerations when installing inverter air conditioners Be sure to secure enough space for servicing/maintenance according to the instructions in the installation manual. Ì Inverter air conditioners may induce noise from other electronic equipment. When selecting a location for installation, maintain sufficient distances from radios, PCs, stereos and the like in consideration of the installation of the air conditioner and power wiring.
At leas t1
m
Indoor unit RC
At least 1m
Branching switch, overcurrent circuit breaker
1.5m At least
Indoor unit
Branching switch, overcurrent circuit breaker Cooling/ heating changeover RC
1m st a m le ast 1.5 At At le 1.5m At least m At least 1.5
Radios, PCs, stereos, etc.
– 33 –
2. Work by Process and Key Points
(10) Air tightness tests Work procedure
1) Completion of refrigerant piping work
2)
3)
Nitrogen pressurization
Evacuation
Check for drop in pressure
Pass
4) Leak check
~Working points~ x Be sure to evacuate the piping before the air tightness test. x Be sure to always use nitrogen gas for the air tightness test. x The air tightness test pressure is the design pressure for air conditioners.
1) Evacuation of refrigerant piping <Work procedure> • Connect the gauge manifold to the service ports on the liquid and gas piping. Operate the vacuum pump until the pressure reaches below –100.7kPaG (–755mmHg). Operate the vacuum pump for about 30 minutes, though it may differ depending the respective piping length.
2) Nitrogen pressurization <Work procedure> (1) Pressurize the liquid and gas piping for each refrigerant circuit according to the following steps: (Be sure to use nitrogen gas.) z Step 1: Pressurize at 0.3 MPaG for approx. 3 minutes
Allows for detection of large leaks
z Step 2: Pressurize at 1.5 MPaG for approx. 5 minutes z Step 3: Pressurize at 4.0 MPaG for roughly 24 hours
Allows for detection of smaller leaks
Ì Even pressurized at 4.0 MPaG, a short time does not allow for detection of smaller leaks. Be sure to pressurize for 24 hours in Step 3.
Example of the air tightness test
[Time chart] Step3
4.0
If no pressure drop,
3.5
2.0
Step2
1.5
1.0
0.5
Step1
Pressure MPaG
0
3 minutes
24 hours 5 minutes
Time
Ì Never pressurize at a pressure above 4.0 MPaG.
– 34 –
PASS
(10) Air tightness tests
3) Check for pressure drop ¡ If there is no pressure drop, it has passed the test. Any differences in ambient temperature between during pressurization and during check for pressure drops will necessitate correction because pressure changes by roughly 0.01 MPaG per 1˚C.
Correction value: (Temperature during pressurization – Temperature during check) x 0.01 MPaG (Example) Pressurization
Pressure used for pressurization 4.00MPaG
Ambient temperature 25°C
24 hours later
3.95MPaG
20°C
In this case, the correction would be 0.05 MPaG so you can determine there has been no pressure drop (indicating a PASS).
4) Leak check x If a drop in pressure has been detected, search for the leak site by applying soapy water to the surface of the piping connections (flares, brazed spots) and charge the hose connections. z It is rare to conduct an air tightness test on everything from the outdoor unit to indoor unit at the same time. If a pressure drop has been detected, it takes a lot of time to check where the leak is. An efficient method to check is on a block-by-block basis in accordance with the work schedule. z After conducting the air tightness test, leaving the pressure between 0.2 and 0.3 MPaG in the piping allows for the prevention of contamination in the piping.
(3)
(1)
Shaft
(2)
<Air tightness tests by the block> (1) For each floor, check from the indoor unit to the vertical pipe within each shaft. (2) Check the above (1) and the vertical piping within each shaft. (3) Check all piping from the indoor unit to the vertical piping to the outdoor unit.
z The work can be conducted efficiently if the pressurization assembly is prepared beforehand.
– 35 –
2. Work by Process and Key Points
(11) Vacuum drying
Work procedure
After passing air tightness test
Vacuum drying
Vacuum test
~What is vacuum drying?~ Using a vacuum pump, the moisture (liquid) in the piping is changed to vapor (gas) and expelled out of the piping in order to dry the inside of the piping. At 1 atmospheric pressure (101.3 kPa or 760 mmHg), the boiling point (evaporation temperature) for water is 100°C. However, the closer the pressure within the piping comes to reaching a vacuum state as a result of using the vacuum pump, the lower the boiling point becomes. Once the boiling point falls below the outdoor temperature, the water will evaporate. <Example> If the outdoor air temperature is 7.2°C, vacuum drying cannot be conducted unless the pressure is lowered below −100.3 kPaG (−752mmHg). Therefore, when conducting vacuum drying, 'selection and maintenance of the vacuum pump' is important. Absolute pressure kPa
mmHg
Gauge pressure kPaG
mmHgG
Gauge pressure kPaG (mmHg)
℃
Necessary degree of vacuum
Absolute pressure kPa (mmHg)
Water boiling point
Outdoor temperature range Evaporating point
Temperature (˚C)
¡ Selection of the vacuum pump Note the following two points when selecting a vacuum pump. 1. Select one that allows for pressure to be brought below –100.7 kPaG (−755 mmHG). 2. Select one that allows for relatively high discharge volume. (One with at least 40 L/min. is recommended.) z Before conducting the vacuum drying work, be sure to check with a vacuum gauge that the pressure reaches a level below −100.7 kPaG. Ì Use special tools for R410A (e.g., gauge manifold, charge hose). Reasons: Refrigerant oils differ between R410A and R22. Using different tools will result in refrigerant oils being mixed between the two, which will result in the development of impurities and the clogging of the refrigerant circuit.
– 36 –
(11) Vacuum drying
<Work procedure> There are two methods of vacuum drying depending on the onsite conditions so selectively use them.
1) Normal vacuum drying…This is the common method. (1) Vacuum drying (1st time) x Connect a gauge manifold to the service ports of the liquid and gas piping and operate the vacuum pump for at least 2 hours. (The pressure must be below −100.7 kPaG or −755 mmHg.) x If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 2 hours, there may either be moisture or a leak in the circuit. Vacuum for 1 more hour to confirm this. x If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 3 hours, check for the leak site. (2) Vacuum test Leave the system in a vacuum state below −100.7 kPaG or −755 mmHg for at least 1 hour and confirm that the gauge indicator does not rise. Ì Conduct evacuation from both the liquid and gas piping. There are various types of functioning components in an indoor unit and evacuating only from one (liquid or gas) piping may result in a break in the vacuum state. z If the gauge indicator rises, there may be moisture remaining or a leak in the circuit.
[Normal vacuum drying time chart] +0.05 MPaG
Pressurized side
Atmospheric pressure
0 MPaG -26.7 kPaG
Vacuumed side
-53.3 kPaG
-80.0 kPaG
-93.3 kPaG
-100.7 kPaG
-101.3 kPaG
Vacuum drying (2 hours)
– 37 –
Vacuum state (1 hour)
Additional refrigerant charge (Refer to the following chapter.)
(11) Vacuum drying
2) Special vacuum drying Special vacuum drying is conducted when there is a risk of moisture within the piping. For example, x When work has been done during the rainy season and there is a risk of condensation within the piping x When the work has taken a long time and there is a risk of condensation within the piping x When there is a risk that rain has entered into the piping during work The special vacuum drying incorporates at least one vacuum break process using nitrogen gas during the normal vacuum drying process. (1) Vacuum drying (1st time) x Connect a gauge manifold to the service ports of the liquid and gas piping and operate the vacuum pump for at least 2 hours. (The pressure must be below −100.7 kPaG or −755 mmHg.) x If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 2 hours, there may either be moisture or a leak in the line. Vacuum for 1 more hour to confirm this. x If the pressure does not fall below −100.7 kPaG or −755 mmHg even after vacuuming for 3 hours, check for a leak site. (2) Vacuum break (1st time) Pressurize with nitrogen to 0.05 MPaG. (The nitrogen gas is a dry nitrogen, so breaking the vacuum state with it increases the effectiveness of the vacuum drying.) (3) Vacuum drying (2nd time) Operate the vacuum pump for at least 1 hour. Determinations: The pressure must reach at least −100.7 kPaG or −755 mmHg. If it does not even after 2 hours of operation, repeat steps (2) (vacuum break) and (3) (vacuum drying). (4) Vacuum test Leave the system in a vacuum state below −100.7 kPaG or −755 mmHg for at least 1 hour and confirm that the gauge indicator does not rise. If the gauge indicator rises, there may be moisture remaining or a leak in the circuit.
Ì Be sure to use nitrogen gas when conducting vacuum break.
[Special vacuum drying time chart] +0.05 MPaG
Pressurized side
Atmospheric pressure
0 MPaG -26.7 kPaG
Vacuumed side -53.3 kPaG
-80.0 kPaG
-93.3 kPaG
-100.7 kPaG
-100.7 kPaG
-101.3 kPaG
Vacuum drying (2 hours)
Additional refrigerant charge
Vacuum break Vacuum state (1 hour)
Vacuum drying (1 hour)
– 38 –
2. Work by Process and Key Points
(12) Additional refrigerant charge Work procedure
After completion of vacuum drying
Calculation of additional refrigerant charge amount based on piping length
Additional refrigerant charge
<Work procedure> (1) Calculation of the additional refrigerant charge amount x Accurately assess the length of the refrigerant piping to calculate the amount of additional refrigerant charge. (For calculating the formula, refer to the equipment design materials for the respective models.) Ì Be sure to enter the calculated additional refrigerant charge amount on the 'additional refrigerant charge instruction label' on the outdoor unit. (The data will be needed for maintenance.) Liquid side stop valve
Refrigerant charge port Outdoor unit
Gauge manifold Valve A
Valve B
Refrigerant cylinder with siphon
Gauge Cylinder
Indoor unit Gas side stop valve
(2) After completing the vacuum drying, leave the air conditioner OFF, open Valve A and charge the calculated additional refrigerant from the cylinder via the liquid side stop valve service port using pressure difference. Ì Be sure to charge the refrigerant in a liquid state. (Cylinders with siphons allow for charging of liquid refrigerant in a standing position.) Ì Use a digital scale to measure. If the refrigerant cannot be charged due to pressure equalization, (3) Close Valve A and then open Valve B. (4) Turn on the outdoor and indoor unit power supplies. (5) Completely open up the gas and liquid side stop valves. Ì Be sure to charge refrigerant from the refrigerant charge port. (6) Turn the additional refrigerant charge operation to ON using the setting mode while leaving the air conditioner OFF. Ì Refer to the 'Service Precautions' label on the outdoor unit's electrical box cover for the procedures regarding additional refrigerant charge operation. (7) Once the required volume of refrigerant has been charged, push the confirmation button (BS1) on the PCB (A1P) to stop the operation.
– 39 –
N o te
TCDB001 All rights reserved. Any unauthorized use, reproduction, modification or distribution of this document is strictly prohibited.
zThe content of this document may change in the future without prior notice.